Safe drinking water is a human right. However it is estimated that 1,1 billion people do not have access to this resource. 20 per cent of the world’s ground and surface water is in Russia, yet at the same time half of the drinking water in Russia doesn’t meet the microbiological requirements that have been set for safe drinking water. The Russian village of Seleznjovo has suffered many years from a poor quality of drinking water, and further, it’s water has been banned for drinking since 2004. This Master’s thesis examines the development of the water supply in the village of Seleznjovo. The aims of this work are: to study the present water supply and problems with it, to study the quality of drinking water and groundwater, to study risk factors in the groundwater area, and, based on this study, to discuss how these risks will affect future water supply development. Water quality was studied by taking water samples from a drilled well, from raw water (surface water), from treated drinking water, and water from consumers’ taps, then analysing the physical, chemical and microbiological quality of the samples. The aesthetics of ground water and drinking water and the state of water supply were studied using a questionnaire. The risk factors in the groundwater area were studied by interviewing the municipal authorities and by working in the field. Additionally, some water quality data from the regional health authority was used in the study. The state of the present water supply is unsatisfactory at every level. The biggest problem is the unsuitable raw water source, which should be replaced. However, it is possible to use groundwater as a raw water source if the water is treated so that it’s condition fulfils the requirements set for drinking water as safe. In this case the water has to be disinfected, pH-adjusted, and treated to reduce the concentration of iron and manganese, and possibly also of fluoride and ammonium. In addition, there has to be low concentration of chlorine after treatment. Contamination of ground water due to rising concentrations of ammonium and chloride has been detected, as has poor microbial quality of the water, and therefore the legally required exclusion area around the drilled well needs to be established immediately. The water quality must be monitored regularly, and the security of the waterworks must be assured, for example by locking the well and waterworks. In addition, the structural stability and durability of the structure of the well needs to be looked after. Additionally, the adequacy of water treatment has to be monitored, to make sure that the water quality remains high in consumers’ taps. The experiences gained from this study can also be used when developing the water supply in other similar villages.